/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/auth/BasicScheme.java,v 1.17 2004/05/13 04:02:00 mbecke Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient.auth;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.httpclient.Credentials;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.UsernamePasswordCredentials;
import org.apache.commons.httpclient.util.EncodingUtil;
import org.apache.commons.logging.Log;

/**
 * <p>
 * Basic authentication scheme as defined in RFC 2617.
 * </p>
 * 
 * @author <a href="mailto:remm@apache.org">Remy Maucherat</a>
 * @author Rodney Waldhoff
 * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
 * @author Ortwin Gl?ck
 * @author Sean C. Sullivan
 * @author <a href="mailto:adrian@ephox.com">Adrian Sutton</a>
 * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
 */

public class BasicScheme extends RFC2617Scheme {

	/** Log object for this class. */
	// private static final Log LOG = LogFactory.getLog(BasicScheme.class);

	/** Whether the basic authentication process is complete */
	private boolean complete;

	/**
	 * Default constructor for the basic authetication scheme.
	 * 
	 * @since 3.0
	 */
	public BasicScheme() {
		super();
		this.complete = false;
	}

	/**
	 * Constructor for the basic authetication scheme.
	 * 
	 * @param challenge
	 *            authentication challenge
	 * 
	 * @throws MalformedChallengeException
	 *             is thrown if the authentication challenge is malformed
	 * 
	 * @deprecated Use parameterless constructor and
	 *             {@link AuthScheme#processChallenge(String)} method
	 */
	public BasicScheme(final String challenge)
			throws MalformedChallengeException {
		super(challenge);
		this.complete = true;
	}

	/**
	 * Returns textual designation of the basic authentication scheme.
	 * 
	 * @return <code>basic</code>
	 */
	public String getSchemeName() {
		return "basic";
	}

	/**
	 * Processes the Basic challenge.
	 * 
	 * @param challenge
	 *            the challenge string
	 * 
	 * @throws MalformedChallengeException
	 *             is thrown if the authentication challenge is malformed
	 * 
	 * @since 3.0
	 */
	public void processChallenge(String challenge)
			throws MalformedChallengeException {
		super.processChallenge(challenge);
		this.complete = true;
	}

	/**
	 * Tests if the Basic authentication process has been completed.
	 * 
	 * @return <tt>true</tt> if Basic authorization has been processed,
	 *         <tt>false</tt> otherwise.
	 * 
	 * @since 3.0
	 */
	public boolean isComplete() {
		return this.complete;
	}

	/**
	 * Produces basic authorization string for the given set of
	 * {@link Credentials}.
	 * 
	 * @param credentials
	 *            The set of credentials to be used for athentication
	 * @param method
	 *            Method name is ignored by the basic authentication scheme
	 * @param uri
	 *            URI is ignored by the basic authentication scheme
	 * @throws InvalidCredentialsException
	 *             if authentication credentials are not valid or not applicable
	 *             for this authentication scheme
	 * @throws AuthenticationException
	 *             if authorization string cannot be generated due to an
	 *             authentication failure
	 * 
	 * @return a basic authorization string
	 * 
	 * @deprecated Use {@link #authenticate(Credentials, HttpMethod)}
	 */
	public String authenticate(Credentials credentials, String method,
			String uri) throws AuthenticationException {

		// //LOG.trace("enter BasicScheme.authenticate(Credentials, String, String)");

		UsernamePasswordCredentials usernamepassword = null;
		try {
			usernamepassword = (UsernamePasswordCredentials) credentials;
		} catch (ClassCastException e) {
			throw new InvalidCredentialsException(
					"Credentials cannot be used for basic authentication: "
							+ credentials.getClass().getName());
		}
		return BasicScheme.authenticate(usernamepassword);
	}

	/**
	 * Returns <tt>false</tt>. Basic authentication scheme is request based.
	 * 
	 * @return <tt>false</tt>.
	 * 
	 * @since 3.0
	 */
	public boolean isConnectionBased() {
		return false;
	}

	/**
	 * Produces basic authorization string for the given set of
	 * {@link Credentials}.
	 * 
	 * @param credentials
	 *            The set of credentials to be used for athentication
	 * @param method
	 *            The method being authenticated
	 * @throws InvalidCredentialsException
	 *             if authentication credentials are not valid or not applicable
	 *             for this authentication scheme
	 * @throws AuthenticationException
	 *             if authorization string cannot be generated due to an
	 *             authentication failure
	 * 
	 * @return a basic authorization string
	 * 
	 * @since 3.0
	 */
	public String authenticate(Credentials credentials, HttpMethod method)
			throws AuthenticationException {

		// //LOG.trace("enter BasicScheme.authenticate(Credentials, HttpMethod)");

		if (method == null) {
			throw new IllegalArgumentException("Method may not be null");
		}
		UsernamePasswordCredentials usernamepassword = null;
		try {
			usernamepassword = (UsernamePasswordCredentials) credentials;
		} catch (ClassCastException e) {
			throw new InvalidCredentialsException(
					"Credentials cannot be used for basic authentication: "
							+ credentials.getClass().getName());
		}
		return BasicScheme.authenticate(usernamepassword, method.getParams()
				.getCredentialCharset());
	}

	/**
	 * @deprecated Use
	 *             {@link #authenticate(UsernamePasswordCredentials, String)}
	 * 
	 *             Returns a basic <tt>Authorization</tt> header value for the
	 *             given {@link UsernamePasswordCredentials}.
	 * 
	 * @param credentials
	 *            The credentials to encode.
	 * 
	 * @return a basic authorization string
	 */
	public static String authenticate(UsernamePasswordCredentials credentials) {
		return authenticate(credentials, "ISO-8859-1");
	}

	/**
	 * Returns a basic <tt>Authorization</tt> header value for the given
	 * {@link UsernamePasswordCredentials} and charset.
	 * 
	 * @param credentials
	 *            The credentials to encode.
	 * @param charset
	 *            The charset to use for encoding the credentials
	 * 
	 * @return a basic authorization string
	 * 
	 * @since 3.0
	 */
	public static String authenticate(UsernamePasswordCredentials credentials,
			String charset) {

		// //LOG.trace("enter BasicScheme.authenticate(UsernamePasswordCredentials, String)");

		if (credentials == null) {
			throw new IllegalArgumentException("Credentials may not be null");
		}
		if (charset == null || charset.length() == 0) {
			throw new IllegalArgumentException(
					"charset may not be null or empty");
		}
		StringBuffer buffer = new StringBuffer();
		buffer.append(credentials.getUserName());
		buffer.append(":");
		buffer.append(credentials.getPassword());

		return "Basic "
				+ EncodingUtil.getAsciiString(Base64.encodeBase64(EncodingUtil
						.getBytes(buffer.toString(), charset)));
	}

}
